Why are there so many species? Ecologists persist in efforts to refine our understanding of how factors like climate, productivity and species interactions contribute to the boundless variety of life on earth. Disturbance receives it share of attention, at least in some forms, but here the authors call attention to one widespread disruptive force—namely, fire—that seems to have escaped in-depth study.

This first global assessment of fire regimes examines temporal and spatial patterns of speciation and plant diversity across 753 terrestrial ecoregions that account for 88 per cent of land surface. The authors combined thermal remote-sensing and climate data with species richness data in hope of unlocking relationships between ecoregional environmental variables and plant diversity. While relying on data from Kier et al. (2005) as their primary data source, the authors also test their results against more than 109 million GBIF-mediated plant occurrences.

Despite known limitations to the study's scale and data biases, clear patterns emerged from analyses of both data sources, suggesting that fire activity is one of the strongest indicators—perhaps the strongest indicator—of coarse-scale plant diversity. Such results suggest the value of further study of fire regimes and an ongoing search for more smoking Gunnera.